Agronomic and biological characteristics of different Amaranthus hypochondriacus L. accessions under varying fertilization regimes

Abstract

Interest in amaranth is associated with its unique nutritional properties, high yield potential, and adaptive properties that ensure its wide use for forage, food, and industrial purposes; in terms of protein, vitamins, biologically active compounds, and lipids it surpasses many cultivated crops. A current research focus is the analysis of agrotechnical and bioecological characteristics of plants of the genus Amaranthus L. under the conditions of the forest-steppe of the Central Chernozem Region. The research goal was to determine the effect of the soil mineral background on the productivity of above-ground biomass of amaranth collection accessions under the foothill conditions of the Republic of North Ossetia-Alania. The experimental work was carried out from 2022 through 2024 in the experimental field of the Research Institute of Biotechnology of the Gorsky State Agricultural University. The soils were represented by leached chernozem of medium depth: humus content of 4.45%; readily hydrolyzable nitrogen of 78 mg·kg; available phosphorus of 94.6 mg·kg; available potassium of 175 mg·kg; soil solution of pH 5.8. The research targets were amaranth collection accessions of different origin: K-62 (Amaranthus cruentus L.) and K-63 (Amaranthus hypochondriacus L.). The accessions K-62 and K-63 revealed high adaptive potential and were able to maintain stable yielding capacity under the agroecological conditions of the Republic of North Ossetia-Alania. The application of the biostimulant product Gumat-Active on a mineral fertilization background (N₆₀P₆₀K₆₀) promoted intensive development of the leaf system. The leaf area reached its maximum at the flowering stage, with the accession K-62 attaining up to 33.4 thousand m²·ha which facilitated effective conversion of solar radiation into biomass. The use of humates produced a statistically significant increase in photosynthetic potential (by 131-142 thousand m²·day·ha compared to the control), thereby providing a foundation for the production of high-quality, environmentally safe products.